158 REPORT—1843. 
Sreconp Recion. 
The ground in the second region, which extends from two to ten fathoms, 
is most generally mud or sand, the former green with a beautiful Fueus, Caw- 
lerpa prolifera, abundant in the Archipelago, but I believe rare elsewhere, 
the latter abounding in Zostera oceanica. Great Holothurie are here found 
in abundance, and, among Mollusea, chiefly burying Conchifera. Nucula 
margaritacea and Cerithium vulgatum are the Testacea most generally distri- 
buted through this region. Those most prolific in individuals are, among 
Gasteropoda, Cerithium vulgatum and lima, Trochus crenulatus and spratt, 
Rissoa ventricosa and oblonga, and Marginella clandestina. Among Lamelli- 
branchiata, Tellina donacina, Lucina lactea, Nucula margaritacea, and Car- 
dium exiguum. Storms disturb this zone by washing up its inhabitants into 
the littoral region. 
The smaller zoophytes, especially encrusting species and such as attach 
themselves to the leaves of Zostera, are frequent. Caryophyllia cyathus 
begins to appear here, ranging however through all the succeeding zones. 
TrstTacrous MoLiuscaA INHABITING THE SECOND REGION. 
Lamellibranchiata. 
Solen tenuis.* Lucina rotundata, 
antiquatus. spinifera. 
Solecurtus strigillatus. transversa. 
Ligula boysii.* Cardium papillosum.* 
Solenomya mediterranea.* rusticum. 
Montacuta sp. exiguum. 
Byssomya guerinii. Cardita sulcata. 
Corbula nucleus.* trapezia. 
Pandora obtusa. Arca barbata. 
rostrata. lactea.* 
Thracia phaseolina. 
Psammobia vespertina. 
Donax venusta. 
Cytherea chione. 
lunata. 
apicalis. 
Venus gallina.* 
verrucosa.* 
aurea.* 
geographica.* 
Tellina donacina.* 
serrata. 
balaustina. 
distorta.* 
Lucina flexuosa. 
pecten. 
lactea.* 
Chiton rissoi.* 
polii.* 
Pectunculus glycimeris.* 
Nucula emarginata.* 
nuclea. 
Modiola barbata.* 
tulipa.* 
discrepans.* 
marmorata.* 
Pinna squamosa. 
Lima squamosa. 
tenera. 
Pecten polymorphus.* 
hyalinus.* 
varius. 
sulcatus. 
Spondylus gadzropus. 
Ostrea plicatula.* 
Chama gryphoides. 
Palliobranchiata. 
0. 
Gasteropoda. 
Calyptraea sinense.* 
Crepidula unguiformis.* 
